5 Laws of Gauges
Double Gauge Pressure Over System Pressure
You always want to have the gauge pointer operate in the center third of the dial. This is the area where the gauge is most accurate. Doubling the gauge pressure also allows for additional over-pressure problems in the system. You can usually go about 15% above the rated gauge pressure before harm is done to the gauge.
Liquid Fill Where Vibration Is Present
Liquid filling is required when vibration is present in your system. The liquid dampens the movement and changes the frequency of the tube tip and lubricates the movement.
Always Use a Restrictor When Pressure Spikes Are Present
Using a restrictor when pulsation is present in a system reducing the amplitude of the pressure spikes/pressure pulses. In high pulsation applications a "super" restrictor is recommended - the super restrictor is about 1/2" long.
Hang a Gauge Upside-Down When High Pressures and Flows Are Present
When high velocity/high pressure flow is present and valves are opening/closing causing the fluid to stop, the gauge to empty and then start flowing again - the fluid will "slam" into the gauge causing a spike and eventually premature failure. Hanging the gauge keeps it full of fluid. And will prevent any high velocity problems.
Never Mount the Gauge Directly Above a High Source of Temperature
Always keep there pressure sensor off to the side of high temperature vessels / pipes allowing convection air currents to draw cooler air to flow around the gauge. There is more to high temperature - cooling coils, capillaries to remote mount the gauge, and stand off pipes.